/*********************************************************************************
 *      Copyright:  (C) 2023 LingYun IoT System Studio.
 *                  All rights reserved.
 *
 *       Filename:  atcmd.c
 *    Description:  This file is lowlevel AT command send and parser API functions
 *                 
 *        Version:  1.0.0(11/08/23)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "11/08/23 16:18:43"
 *                 
 ********************************************************************************/

#include <ctype.h>
#include "logger.h"
#include "atcmd.h"

/*  Description: this function used to send an AT command from serial port and wait for reply message from
 *               the communication module, and it will return once get expet/error string or timeout.
 *
 *    Arugments:
 *         $comport: the serial port which connected to GPRS/3G/4G/NB-IoT/WiFi/BLE/Zigbee/LoRa...
 *              $at: the AT command need to be sent, without "\r\n"
 *         $timeout: wait for module reply for AT command timeout value, unit micro seconds(ms)
 *          $exepct: the expect string reply from communication module
 *           $error: the error string reply from communication module
 *           $reply: the module reply message output buffer
 *            $size: the output buffer ($reply) size
 *
 * Return value: <0: Function error   0: Got error string   1: Got expect string 2: Receive util timeout
 *
 */

int send_atcmd(comport_t *comport, char *at, unsigned long timeout, char *expect, char *error, char *reply, int size)
{
    int                    i, rv = 0;
    int                    res = ATRES_TIMEOUT;
    int                    bytes = 0;
    char                   buf[ATCMD_REPLY_LEN] = {'\0'};
    char                   atcmd[ATCMD_LEN] = {'\0'};

    if( !comport || !at )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    if( comport->fd <= 0 )
    {
        log_error("comport[%s] not opened\n");
        return -2;
    }

    /* flushes both data received but not read, and data written but not transmitted in serial port */
    tcflush(comport->fd, TCIOFLUSH);

    snprintf(atcmd, sizeof(atcmd), "%s%s", at, AT_SUFFIX);
    rv=comport_send( comport, atcmd, strlen(atcmd) );
    if(rv < 0)
    {
        log_error("send AT command \"%s\" to \"%s\" failed, rv=%d\n", at, comport->devname, rv);
        return -3;
    }

    res = ATRES_TIMEOUT;
    memset( buf, 0, sizeof(buf) );

    for(i=0; i<timeout/10; i++)
    {
        if( bytes >= sizeof(buf) )
            break;

        rv=comport_recv( comport, buf+bytes, sizeof(buf)-bytes, 10);
        if(rv < 0)
        {
            log_error("send AT command \'%s\' to \'%s\' failed, rv=%d\n", at, comport->devname, rv);
            return -3;
        }

        bytes += rv;

        if( expect && strstr(buf, expect) )
        {
            log_debug("send AT command \"%s\" and got reply \"OK\"\n", at);
            res = ATRES_EXPECT;
            break;
        }

        if( error && strstr(buf, error) )
        {
            log_debug("send AT command \"%s\" and got reply \"ERROR\"\n", at);
            res = ATRES_ERROR;
            break;
        }
    }

    if( bytes > 0 )
        log_trace("AT command reply:%s", buf);

    if( reply && size>0 )
    {
        bytes = strlen(buf)>size ? size : strlen(buf);
        memset(reply, 0, size);
        strncpy(reply, buf, bytes);

        log_debug("copy out AT command \"%s\" reply message: \n%s", at, reply);
    }

    return res;
}


/*
 *  Description: Send AT command which will only reply by "OK" or "ERROR", such as AT:
 *                 Reply:   \r\nOK\r\n
 * Return Value: 0: OK     -X: Failure
 */
int send_atcmd_check_ok(comport_t *comport, char *at, unsigned long timeout)
{
    int                     rv;

    if( !comport || !at )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    rv=send_atcmd(comport, at, timeout, AT_OKSTR, AT_ERRSTR, NULL, 0);
    if( ATRES_EXPECT == rv )
    {
        return 0;
    }
    else
    {
        return -2;
    }
}


/*
 *  Description: Send AT command which will reply by a value directly in a single line, such as AT+CGMM:
 *                  Reply:   \r\nEC20F\r\nOK\r\n
 *
 * Return Value: 0: OK     -X: Failure
 */
int send_atcmd_check_value(comport_t *comport, char *at, unsigned long timeout, char *reply, int size)
{
    int                     rv, len;
    char                    buf[ATCMD_REPLY_LEN];
    char                   *ptr_start = buf;
    char                   *ptr_end;

    if( !comport || !at || !reply || size<=0 )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    rv = send_atcmd(comport, at, timeout, AT_OKSTR, AT_ERRSTR, buf, ATCMD_REPLY_LEN);
    if( rv <= 0 )
    {
        return -2;
    }

    /* Skip the echo back command line */
    if( !strncmp(buf, at, strlen(at)) )
    {
        ptr_start=strchr(buf, '\n');
        if( !ptr_start )
        {
            log_error("reply message got wrong\n");
            return -3;
        }

        ptr_start++;   /* skip '\n'  */
    }

    /* find end reply string "\r\nOK\r\n"  */
    ptr_end = strstr(ptr_start, AT_OKSTR);
    if( ptr_end )
    {
        len = ptr_end - ptr_start;
    }
    else
    {
        len = strlen(buf) - (ptr_start-buf);
    }

    memset(reply, 0, size);

    len = len>size ? size : len;
    memcpy(reply, ptr_start, len);

    return 0;
}

/*
 *  Description: Parser the $value from $key like "xxx: " line, such as AT+CSQ:
 *                  Reply:   \r\n+CSQ: 26,99\r\nOK\r\n
 *
 * Return Value: 0: OK     -X: Failure
 */
int parser_request_value(char *buf, char *key, char *value, int size)
{
    char                   *ptr;
    int                    i = 0;

    if( !buf || !key || !value || size<=0 )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    ptr = strstr(buf, key);
    if( !ptr )
    {
        log_debug("Not found key \"%s\" in %s\n", key, buf);
        return -2;
    }

    ptr=strchr(ptr, ':');  /* found ':' before the value */
    if( !ptr )
    {
        log_debug("Not found ':' before value\n");
        return -3;
    }
    ptr++;   /* skip ':'  */

    if( *ptr == '\"' ) /* skip " */
        ptr++;

    memset(value, 0, size);
    while(*ptr!='\r' && i<size-1)
    {
        if( !isspace(*ptr) && *ptr!='\"') /* skip space,\r,\n ...  */
            value[i++] = *ptr;
        ptr ++;
    }

    ptr++; /* skip  */

    return 0;
}

/*
 *  Description: Send AT command which will reply by the value  with a prefix "+CMD: " line, such as AT+CSQ:
 *                  Reply:   \r\n+CSQ: 26,99\r\nOK\r\n
 *
 * Return Value: 0: OK     -X: Failure
 */
int send_atcmd_check_request(comport_t *comport, char *at, unsigned long timeout, char *reply, int size)
{
    int                     i = 0;
    int                     rv;
    char                    buf[ATCMD_REPLY_LEN];
    char                   *ptr;

    if( !comport || !at || !reply || size<=0 )
    {
        log_error("Invalid input arguments\n");
        return -1;
    }

    rv = send_atcmd(comport, at, timeout, AT_OKSTR, AT_ERRSTR, buf, ATCMD_REPLY_LEN);
    if( rv <= 0 )
    {
        return -2;
    }

    ptr=strchr(buf, '+');  /* found '+' before the value */
    if( !ptr )
    {
        log_error("reply message got wrong\n");
        return -3;
    }
    ptr++;   /* skip '+'  */


    ptr=strchr(buf, ':');  /* found ':' before the value */
    if( !ptr )
    {
        log_error("reply message got wrong\n");
        return -3;
    }
    ptr++;   /* skip ':'  */

    if( *ptr == '\"' ) /* skip " */
        ptr++;

    memset(reply, 0, size);
    while(*ptr!='\r' && i<size-1)
    {
        if( !isspace(*ptr) && *ptr!='\"') /* skip space,\r,\n ...  */
            reply[i++] = *ptr;
        ptr ++;
    }

    return 0;
}